The present invention relates to quick connect couplers and in particular a quick connect coupler utilizing pressurized air to release the coupler from a mating stud. The quick connect coupler is particularly adapted for use in connecting an extension bar to a movable mold plate in a molding apparatus.
In a conventional molding apparatus, a molded part is produced by injecting mold material into a cavity formed between a stationary and a movable mold half mounted to a mold press. The stationary mold half is mounted on a front stationary platen of the mold press and the movable mold half is mounted to a movable platen which is generally slidably mounted on tie-rods extending from the front stationary platen to a rear stationary platen of the mold press. The movable platen is hydraulically advanced toward and away from the front stationary platen during a mold cycle to move the movable mold half between a closed and open alignment with the stationary mold half.
Mold material is injected into the mold cavity when the movable mold half is positioned in the closed position relative to the stationary mold half. Once the molded part has set, the movable mold half is separated from the stationary mold half, and the molded part is then ejected from between the two mold halves using an ejector assembly.
A typical ejector assembly comprises a plurality of ejector pins, which are connected to a mold ejector plate slidably mounted relative to the movable mold half. The mold ejector plate is connected to a press ejector plate by extension bars or tie in bars. The ejector pins are slidably mounted within the movable mold half in bores which open into the mold cavity. The ejector pins are advanceable between a retracted position within the bores to an extended position wherein a portion of each ejector pin extends into the mold cavity for ejecting the molded part out of the cavity.
The mold ejector plate is typically mounted within a chamber in the moveable mold half. The mold ejector plate is mounted in the chamber to permit it to slide toward and away from the mold cavity. The extension bars extend through aligned holes in the movable platen and a rear wall of the movable mold half and connect the mold ejector plate to the press ejector plate.
In ejecting the molded part from the mold, the movable platen is first advanced away from the front stationary platen to pull the movable mold half away from the stationary mold half. After the moveable mold half has separated from the stationary mold half and advanced to a fully open position, the press ejector plate is hydraulically advanced forward to advance the mold ejector plate forward relative to the moveable mold half and to advance the ejector pins from a retracted to an extended position thereby ejecting or separating the molded part from the moveable mold half.
The molded part then typically falls from between the stationary and moveable mold halves. The press ejector plate is then retracted hydraulically and the mold halves are advanced to a closed alignment and the cycle is repeated.
The stationary and moveable mold halves are removably securable to the mold press such that different molds may be interchangeably connected to the mold press to permit efficient utilization. In changing out a mold, the moveable mold half must be disconnected from the moveable platen and the extension bars must be disconnected from the mold ejector plate contained within the moveable mold half. The new moveable mold half must then be connected to the moveable platen and the extension bars must then be connected to the mold ejector plate.
It is known to use ball bearing type quick connect coupler assemblies for connecting the extension bars to the mold ejector plate. Such assemblies generally comprise a coupler stud bolted to the mold ejector plate and a quick connect female coupler bolted to the associated end of the extension bar. The female coupler includes a plurality of ball bearings mounted therein which are advanceable into and out of engagement with an annular groove in the neck of the stud. The ball bearings are held in the annular groove in the neck of the stud by a locking collar or sleeve slidably mounted on the female coupler to secure the stud to the female coupler. An annular recess is formed on an inner surface of the locking collar. The locking collar is slidable to align the annular recess therein with the ball bearings to permit the ball bearings to advance out of engagement with the annular groove in the male stud and permit separation of the stud from the female coupler.
It is also known to normally bias the locking collar into engaging relationship with the ball bearings holding the balls in the annular groove in the stud and to use pressurized air to advance the locking collar out of engaging relationship with the balls. Pressurized air must be supplied to the coupler to maintain the balls in a disengaged position to permit the female coupler to be connected to and separated from the stud. If pressurized air is not supplied to the coupler, the balls are held in an inward position preventing manual coupling of the coupler with the stud. If the coupler is hydraulically advanced toward engagement with the stud without pressurized air supplied to the coupler, the stud will drive the balls outward against the collar, damaging either the collar or stud or both.
There remains a need for a quick connect coupler which may be actuated remotely utilizing pressurized air to engage and disengage an associated stud and which is not prone to damage if the coupler and stud are brought into engagement without pressurized air being supplied to the coupler.
The present invention comprises a female coupler of the type having a plurality of balls maintained in ball receiving bores in the body of the female coupler and selectively advanceable into and out of a stud receiving bore in the female coupler for mechanically engaging a stud upon advancement of the stud into the stud receiving bore. The balls are held in the stud receiving bore in engagement with the stud by a locking collar on the female coupler. An annular groove is formed on an inner surface of the outer locking collar. The collar is slidable forward relative to the female coupler body to advance the annular groove in the locking collar into alignment with the balls such that the balls can advance radially outward into the annular groove to permit withdrawal of the stud from the stud receiving bore. The female coupler may be remotely disengaged from the stud by supplying pressurized air to the female coupler to act against a plunger connected to the outer locking collar to drive the outer locking collar forward such that the annular groove therein is advanced into alignment with the ball receiving bores in the female coupler body. A blocking sleeve is slidably mounted on a shaft of the plunger within the stud receiving bore and spring biased forward so as to slide across the ball receiving bores in the female coupler body as the stud is withdrawn from the stud receiving bore. Advancement of the blocking sleeve across the ball receiving bores holds the balls out of the stud receiving bore until the stud is subsequently advanced into the stud receiving bore to the point that an annular groove in the stud is aligned with the stud receiving bore.
The female coupler is particularly adapted for connection to an extension bar for connecting a press ejector plate to a mold ejector plate. The female coupler is removably securable to a first end of the extension bar which is connected at an opposite end to the press ejector plate. The stud is adapted to be bolted to the mold ejector plate. The extension bar is thereby adapted for relatively quick connection to and remote release from the mold ejector plate to permit relatively rapid and safe change outs of the molds in a mold press. The female coupler is connected to a source of pressurized air through an airflow passageway extending through the extension bar.
The objects of this invention include: providing a quick connect coupler for quickly making a mechanical connection between the coupler and a cooperating stud which may be released remotely; to provide such a quick connect coupler which uses pressurized air to disconnect the coupler from the stud; to provide such a quick connect coupler which may be reconnected to a stud without supplying pressurized air to the coupler; and to provide such a quick connect coupler which is particularly well adapted for use in connecting an extension bar to a mold ejector plate.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.